Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
A variety of applications can be provided by wearable devices, e.g., devices configured to be mounted to a wrist or other location of a user's body. Such devices can provide information and/or communications functions to the user (e.g., by providing an indication of the current time or the user's location, by providing the content of an email received by the user). Such devices could include one or more sensors configured to detect properties of the user's body (e.g., a blood pressure, a heart rate, a blood oxygen saturation, electrical activity of the heart) and/or of the environment of the user (e.g., an ambient temperature, a barometric pressure) and to record, provide indications of, communicate to external systems, or otherwise use such detected properties. In some examples, such a wearable device can be configured to connect to an external system, e.g., to receive energy from the external system to recharge a battery of the wearable device, to communicate with/via the external system, or to provide some other application of the wearable device.